DataFrame.groupby

danfo.DataFrame.groupby(columns) [source]
Parameters
Type
Description
Default
columns
Array
The names of a column(s) in the DataFrame to group by
​
Returns:
       return DataFrame.groups
Examples
Groupby a single column from a DataFrame
Node
Browser
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const dfd = require("danfojs-node")
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​
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let data = [["Pear", 2, 3], ["Pear", 5, 6], ["Apple", 30, 40], ["Apple", 89, 78]]
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let cols = ["A", "B", "C"]
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​
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let df = new dfd.DataFrame(data, { columns: cols })
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let group_df = df.groupby(["A"])
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console.log(group_df)
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​
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//GroupBy Object
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GroupBy {
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  key_col: [ 'A' ],
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  col_dict: { Pear: [ [Array], [Array] ], Apple: [ [Array], [Array] ] },
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  data: [
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    [ 'Pear', 2, 3 ],
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    [ 'Pear', 5, 6 ],
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    [ 'Apple', 30, 40 ],
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    [ 'Apple', 89, 78 ]
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  ],
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  column_name: [ 'A', 'B', 'C' ],
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  data_tensors: {
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    Pear: DataFrame {
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      '$isSeries': false,
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      '$config': [Configs],
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      '$data': [Array],
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      '$dataIncolumnFormat': [Array],
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      '$index': [Array],
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      '$dtypes': [Array],
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      '$columns': [Array]
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    },
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    Apple: DataFrame {
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      '$isSeries': false,
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      '$config': [Configs],
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      '$data': [Array],
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      '$dataIncolumnFormat': [Array],
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       ...
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      '$columns': [Array]
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    }
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  },
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  col_dtype: [ 'string' ]
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}
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1
​
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A groupby operation will return a GroupBy class object. You can apply any of the following operation on the groupby result:
1.
​count​
2.
​sum​
3.
​std​
4.
​var​
5.
​mean​
6.
​cumsum 
7.
​cummax​
8.
​cumprod​
9.
​cummin​
10.
​max​
11.
​min​
Example of Groupby and apply a sum function
Node
1
const dfd = require("danfojs-node")
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​
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let data = [["Pear", 2, 3], ["Pear", 5, 6], ["Apple", 30, 40], ["Apple", 89, 78]]
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let cols = ["A", "B", "C"]
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let df = new dfd.DataFrame(data, { columns: cols })
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let group_df = df.groupby(["A"]).sum()
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​
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group_df.print()
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​
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╔════════════╤═══════════════════╤═══════════════════╤═══════════════════╗
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║            │ A                 │ B_sum             │ C_sum             ║
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╟────────────┼───────────────────┼───────────────────┼───────────────────╢
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║ 0          │ Pear              │ 7                 │ 9                 ║
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╟────────────┼───────────────────┼───────────────────┼───────────────────╢
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║ 1          │ Apple             │ 119               │ 118               ║
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╚════════════╧═══════════════════╧═══════════════════╧═══════════════════╝
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Groupby a two columns from a DataFrame
Node
Browser
1
const dfd = require("danfojs-node")
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​
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let data = [["Pear", 2, 3], ["Pear", 2, 6], ["Apple", 30, 40], ["Apple", 89, 78]]
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let cols = ["A", "B", "C"]
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let df = new dfd.DataFrame(data, { columns: cols })
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let group_df = df.groupby(["A", "B"]).sum()
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​
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group_df.print()
Copied!
1
​
Copied!
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╔════════════╤═══════════════════╤═══════════════════╤═══════════════════╗
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║            │ A                 │ B                 │ C_sum             ║
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╟────────────┼───────────────────┼───────────────────┼───────────────────╢
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║ 0          │ Pear              │ 2                 │ 9                 ║
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╟────────────┼───────────────────┼───────────────────┼───────────────────╢
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║ 1          │ Apple             │ 30                │ 40                ║
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╟────────────┼───────────────────┼───────────────────┼───────────────────╢
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║ 2          │ Apple             │ 89                │ 78                ║
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╚════════════╧═══════════════════╧═══════════════════╧═══════════════════╝
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DataFrame.addColumn

DataFrame.column

Last modified 6d ago

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Contents

Examples

Groupby a single column from a DataFrame

Example of Groupby and apply a sum function

Groupby a two columns from a DataFrame